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3-D Q-coda attenuation structure at Mt Etna (Italy).
- Source :
-
Geophysical Journal International . Oct2021, Vol. 227 Issue 1, p544-558. 15p. - Publication Year :
- 2021
-
Abstract
- Three dimensional attenuation images of Mt Etna volcano obtained by the analysis of Q -coda from local volcano-tectonic earthquakes are presented in this work. Seismic sources are confined inside the Etna structure with a maximum focal depth of 35 km below the sea level. The space distribution of the attenuation values was calculated by using 3-D weighting functions derived by the sensitivity kernels of Pacheco & Snieders and approximated by a polynomial interpolation, represented in the maps by using a backprojection method. Data were analyzed in four bands with central frequency placed at 1.5, 3, 6 and 12 Hz, respectively. We observed a frequency dependence of Q -coda with values that range from 55 at 1.5 Hz to 218 at 12 Hz. Q -coda space distribution in the Etna area shows almost uniformity in the average attenuation in the first 35 km below the surface. The images were derived with a resolution of 5 km. We observe as one of our main conclusions that Q -coda attenuation space anomalies are correlated with the areas of highest structural heterogeneities and are distributed along the well-known tectonic structures which characterize the crust in Mt Etna region. Previous and numerous velocity and attenuation images describing the structure of Mt Etna support our main conclusion: high Q -coda volumes almost coincide with the zones marked by high velocity and relative low total attenuation for direct waves. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0956540X
- Volume :
- 227
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Geophysical Journal International
- Publication Type :
- Academic Journal
- Accession number :
- 152419717
- Full Text :
- https://doi.org/10.1093/gji/ggab235